Internal coordination between hydraulics and stomatal control in leaves
Internal coordination between hydraulics and stomatal control in leaves
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DOI：
10.1111/j.1365-3040.2008.01865.x
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发表时间：
2008-11-01
影响因子：
7.3
通讯作者：
Jordan, Gregory J.
中科院分区：
文献类型：
--
作者：
Brodribb, Tim J.;Jordan, Gregory J.
气孔对叶片-大气水汽压梯度（D-I）变化的响应是一个决定叶片气体交换日进程的关键而又神秘的过程。表皮细胞水合作用的变化被认为是驱动这种反应的原因，由叶片的蒸腾速率和水力传导率介导。在这里，我们研究是否种属特异性变化的敏感性叶片扰动的D-1是有关的水运输的效率在叶（叶导水率，K-叶）。我们发现叶片中的最大液相电导（K-叶）和气相电导（g（max））之间具有良好的相关性，但归一化D-1敏感性与K-叶之间没有直接相关性。只有在考虑到K叶和g（max）之间的强关系后，K叶对我们8个物种的不同样本中D-1敏感性的影响才是重要的。因此，g（max）/K-叶的比值与气孔对D-1的敏感性密切相关。该比值是气孔对D-I变化的水力缓冲程度的指标，并且相对于K叶具有高g（max）的物种对D-I扰动最敏感。尽管这种现象具有潜在的高适应性意义，但我们没有发现我们物种的显着系统发育或生态趋势。
The stomatal response to changing leaf-atmospheric vapour pressure gradient (D-l) is a crucial yet enigmatic process that defines the daily course of leaf gas exchange. Changes in the hydration of epidermal cells are thought to drive this response, mediated by the transpiration rate and hydraulic conductance of the leaf. Here, we examine whether species-specific variation in the sensitivity of leaves to perturbation of D-l is related to the efficiency of water transport in the leaf (leaf hydraulic conductivity, K-leaf). We found good correlation between maximum liquid (K-leaf) and gas phase conductances (g(max)) in leaves, but there was no direct correlation between normalized D-l sensitivity and K-leaf. The impact of K-leaf on D-l sensitivity in our diverse sample of eight species was important only after accounting for the strong relationship between K-leaf and g(max). Thus, the ratio of g(max)/K-leaf was strongly correlated with stomatal sensitivity to D-l. This ratio is an index of the degree of hydraulic buffering of the stomata against changes in D-l, and species with high g(max) relative to K-leaf were the most sensitive to D-l perturbation. Despite the potentially high adaptive significance of this phenomenon, we found no significant phylogenetic or ecological trend in our species.